In a diesel engine, because the fuel distribution is nonuniform the

burned gas temperature is nonuniform. Consider small fuel$-$air mixture

elements initially at $1000$ K and $6\mathrm{.}5$ MPa at top$-$center with a range of

equivalence ratios. Each element burns at essentially constant pressure.

Calculate $($using the charts in Chap. $4,$ or an appropriate chemical

equilibrium thermodynamic computer code$)$ the burned gas temperature for

mixture equivalence ratios of $0\mathrm{.}4,0\mathrm{.}6,0\mathrm{.}8,1\mathrm{.}0,1\mathrm{.}2.($Assume the fuel is

isooctane.$)$ Note: the reaction zone in the main diesel combustion phase $($a

diffusion flame$)$ is stoichiometric.